KANDAHAR, Afghanistan (Reuters) -- A roadside bomb killed nine Afghan civilians as their van drove along a road in a southern Taliban stronghold near the Pakistan border, a provincial official has said.

Also in the south, a foreign soldier under NATO's command was killed by a roadside bomb on July 16, NATO-led forces said in a statement. Defense officials in London identified the dead soldier as British.

July has already become the bloodiest month for foreign forces in the eight-year-old war in Afghanistan.

Earlier this month U.S. troops launched a major operation in the south, the biggest offensive against the Taliban under U.S. President Barack Obama's new regional strategy to defeat the Islamist insurgents and their allies and stabilize Afghanistan.

Under Obama's strategy, U.S. force strength in Afghanistan is rising from 32,000 at the beginning of this year to a projected 68,000 by year's end.

Homemade bombs planted in the road are by far the most lethal weapon deployed by Taliban insurgents, frequently killing civilians as well as the foreign and Afghan government troops they traditionally target.

Saifullah Hakim, a senior police officer in southern Kandahar Province's border town of Spin Boldak, said the bomb that killed the civilians was apparently planted by insurgents to strike convoys of Afghan and foreign troops.

Soldiers often use the road where the bomb was planted.

Hakim said the passenger van had 11 civilians on board and was heading for a shrine when the bomb went off. Five children and two women were among the dead. Two women were wounded.

Violence this year has reached its worst level since U.S.-backed Afghan forces toppled the Taliban in 2001. Some 800 civilians were killed in Afghanistan between January and May, a 24 percent increase from the same period in 2008, according to UN figures released last month.

Thousands of U.S. Marines have launched the biggest operation of the war in Helmand, next to Kandahar. British forces have also launched their biggest operation in a different part of Helmand.

Violence has spiked across the country since those operations were launched.

In southeastern Paktika Province, Afghan and foreign forces killed 11 Taliban insurgents during a joint operation and air strikes in the Waze Zadran district overnight, provincial district chief Abdul Wali Zadran and NATO officials said.